In the thrilling men's 4x100 relays event at the world championships, a US disqualification sees China go from bronze to silver in a historic race.
Kenyan Edna Kiplagat defied hot and humid conditions and a brave front-running display from Italian Valeria Straneo to become the first woman to retain the world marathon title on Saturday.
Ukraine's 'Iron Lady', Natalia Semenova, bravely competed in discus qualifying at the world championships on Saturday after suffering concussion and a broken, bloodied nose in a freak accident just before the event began.
Trinidad and Tobago sprinter Kelly-Ann Baptiste, who won a world 100m bronze medal in 2011 and was a real prospect for Moscow, has tested positive for a banned substance, the Trinidad Express newspaper reported on Saturday.
Chinese sprinter Zhang Peimeng cut his own national record to 10.00 seconds in the semifinal of men's 100m race at the IAAF World Championships Sunday.
The world athletics championships got off to low-key but high-humidity start in front of a few hundred hardy fans scattered around the 81,000 Luzhniki Stadium on Saturday, with star attraction Usain Bolt ready to be unleashed in the evening.
Athletes competes in the IAAF World Athletics Championships at the Luzhniki stadium in Moscow August 10, 2013.
Chinese race walkers, spearheaded by Olympic champion Chen Ding, will carry on Chinese team's hope for gold medals in the 2013 IAAF World Championships to open here on Saturday.
Athletics will return to four-year bans for first-time dopers in 2015, putting an end to the practice of Olympic athletes suspended for doping being allowed to compete in the following Games.